LowFile-scopeC# Plug & play

Use IReadOnlyList for immutable collections

Expose read-only views (IReadOnlyList/IReadOnlyCollection) from APIs that should not allow mutation.

Why this matters

Encodes intent and prevents accidental modifications.

Side-by-side examples engineers can pattern-match during review.

Avoid

public List<Item> Items { get; }

Prefer

public IReadOnlyList<Item> Items { get; }

Bad

List<T> exposed publicly

Good

IReadOnlyList<T> exposed

From the same buckets as this rule.

Critical
Check consent and role-based authorization before returning ePHI
Handlers must verify the requester’s role and a valid consent/relationship (e.g., care team assignment) before disclosing ePHI; include Purpose-Of-Use in the decision and audit the outcome.
compliance-hipaasecurity-hardening+2
Critical
Children's data: verify age and parental consent
If data subject is a child/adolescent, require age verification and parental/legal guardian consent prior to processing; deny processing otherwise and do not store the payload.
compliance-lgpdapi-conventions+1
Critical
Disallow public ingress without explicit allowlist
For Ingress/Service of type LoadBalancer, require host/path allowlist and TLS; forbid 0.0.0.0/0 exposure without WAF or Auth.
infra-as-codesecurity-hardening+1